insinuación, f., hint, suggestion.
insinuante, insinuating, obliging, ingratiating.
insistir (en), to insist.
insolencias, effrontery, forwardness.
insólito, unaccustomed.
insomnio, insomnia.
inspección, f., inspection.
inspirar, to inspire, cause.
instalación, f., installation.
instantáneamente, instantly.